Metal furnace.



N0- 828,881. PATENTED AUG. 21, 1906.

' A. FISHER.

METAL FURNACE. APPLICATION rum) JULY 14. 1005.

3 8HEETS-BHBET 1.

I PATENTED AUG. 21, 1906.

A. FISHER.

METAL FURNACE.

APPLICATION FILED JULY 14. 1905.

a SHEETS-SHEET 2.

furnace acts to clog ALFRED FISHER, OF CHICAGO, ILLINOIS.

METAL FURNACE.

Specification of Letters Patent.

Patented Aug. 21, 1906.

Application filed Julyli, 1905. Serial Ho. 269.680.

To all whom it may concern:

Be it known that I, ALFRED FISHER, a citizen of the United States, and a resident of Chicago, in the county of Cook and State of .Illinols, have invented certain new and use- I -ful Improvements in Metal Furnaces;an d I do hereby declare that the following is a clear and exact description of the same, reference being had to the accompanyingdrawings, and to the letters of reference marked thereon, which form apart of this specification.

This invention relates to improvements in furnaces, and more particularly to a cruciblefurnace.

Heretofore of the brass and any other metal furnaces of the class in which crucibles are used the air-blast has usually been directed against the crucible, with the effect of quickly Wearing or eroding the same away, soon reducing the strength of the crucible sufliciently to endanger the loss of the charge by breakage. Furt ermore, in such furnaces heretofore the heat has been usually applied unequally to different parts of the crucible, with the effect of heating the charge, unevenly and not only endangering the furnace and crucible, but burning a part of the metal before the remainder has been thoroughly melted. Sometimes also in devices of the class the furnace has been so constructed that the breakage of the crucible within the the furnace, and should the metal harden t erein itis practically impossible to remove the same from the furnace without injury to the furnace.

The object 'of this invention is to provide a construction in which all parts of the crucible ;must receive. the same heatin effect, insuring uniform temperature in a1 parts of the crucible, thereby melting the metal evenly, insuring a uniform reduction of the charge,

" and in which the blast and heat of the furnace flow centrifugally around the crucible, affording maximum heatin effect but minimum wearing or eroding e ect upon the crucible.

A further object of the invention is to providea nozzle in connection with the furnaceblast burnersv whereby the fuel-sup ly and the blast can be accuratel regulated work required, enabling the operator to se- 7 cure a range of temperaturelusually impossible heretofore and also enabling the opera tion of the furnace to be perfectly controlled and enabli the furnace to be used continuously, enab ing many charges to be taken circular plate a,

to the lined spout a, and on the o therefromuas compared with the furnaces.

heretofore in use.

The invention consists in the matt rs hereinafter described, and more fully pointed out and defined in the appended claims.

In the drawings, Fi e 1 is a front elevation, partly broken, og a furnace embodying my invention. Fig. 2 is a rear'elevation of the same. Fi 3 is a central vertical section of the same. ig'. 4 is a top plan view thereof, partly in section. Fig. 5 is a central horizontal section of a furnace embodying my invention and nprovided with two urners. Fig. 6 is an e arged horizontal section of a burner embodied in my invention. Fig. 7 is a side elevation of the same. Fig. 8 is a section taken on'line 8 8 of Fig. 6.

As-shown in the drawin s, said furnace embraces a bottom layer of e-clay, fire-brick, or other suitable refractory material (indicated by A) and supported, as shown, on a referably of metal- Connected with said ottom plate by'bolting or riveting is a side plate a which extends u wardly above the base layer A and alfor s apart of the retaining-casing for the wall of fire-bricks a, which on the outer side tapers conically upward and on the inner side converges upwardly, providing a circular pot or furnace, which at the bottom curves inwardly, affording a conical chamber. Inclosing said-fire-brick a? is an outer jacket or lining a of sheet metal, rigidly bolted or otherwise secured tot e upper edge to the jacket or liner 0., and su 'orted on the top of said fire-bricka are firefiirick a, the outer sides of which extend vertically and the inner sides of which are shaped to afford when built into the furnace a cylindric chamber of practically uniform diameter. Extending to the top' of secured on the upper edge of the jacket-s act a. On the top of said sheet or plate a. and secured thereto by means of an angle-iron connecting-band a is a top plate a, rigidly bolted thereto and having a central aperture above the furnace of greater diameter than the interior diameter of the'furnace.

Extending outwardly and downwardly through the front of the furnace and the jacket-wall a, at the bottom thereof, is a assage a", at the outer end of which is a c agposite side of t e furnace and opening throng the wall thereof, through one or more of the fire-bricks a is a isa'jacketorlinera, of metal, 'dly- IOO stack a, constructed of sheet metal and lined with fire-bricks or other refractory material.

Hinged on the rear side of the furnace upon lugs b, rigidly bolted to the rear wall of the furnace, is a lid com rising a circularly-bent OZLSt-Hlfitfid outer casing B, affording an upwardly-extending wall having an.inwardly directed lower flange afiording an aperture therethrough coincident with the aperture inthe plate a and in whichis' supported a fireclay or fire-brick filler I), provided with a central upwardly-enlarging aperture therethrough having at its bottom approximately the diameter of the crucible to be contained in the furnace. A cover-plate b is rigidly bolted or otherwise secured and provided with a central aperture thereth'rough of greater diameter than the aperture through the fire-clay containedin the'lid. Asshown, rigid arms I) extend rearwardly from said lid and are provided at their outer ends with counterweights I)" and, as shown, are apertured intermediate the ends to receive a pintle-rod b which passes through the ends of the brackets or arms b and through said arms and affords the hinge for said lid. As shown, also, a removable cover is provided to close the central aperture throughthe hinged lid and comprises aca's't or sheet metal casing I), having secured at the top thereof apertured lugs or handles 1) and at its bottom provided with an inwardly-turned flange or ip, as shown in Fi 3, and in which is secured a fire-clay or re-brick or any suitable refractory lining. A ventaerture is also provided through thetop of said removable cover to provide for the escape of apart of the fumes or gases. The front side of the lid is adapted to be locked to the front cas ng or wall of the furnace. A forwardly-directed bracket C is provided at its end with a fever 0, j ournaled transversely therein and having a cam c thereon adapted to engage a hook c pivotally engaged onthefront wall or casing of the furnace, so that when said lid is closed and the hook or latch c swung over said cam operation of the lever acts to positively seoure'the lid in place.

Within the furnace is seated an upwardlytapering centra-l conical block or pedestal D, having a flat top and having its sides curved inwardly to correspond with the side walls. Upon this pedestal is supported a crucible D. Said block or pedestal is of course constructed of fire-clay or other refractoryma'terial and is of a height to elevate the top of the crucible to near the top of the furnace, as shown in Fig. 3.

One or more blast-burners are provided adapted for the use of crude oil or any suitable hydrocarbon, and, as shown, each comprises a conical twyer affording a restricted nozzle andconstruc'ted of cast metal or any suitable material and which is shown as secured in the outer casing or wall of the forthe restriction in the twyer and the outer end of which is'connected in and communicates through the outer end of the twver, by means of a needle-valve 6, with a crude-oil or other hydrocarbon pipe e Secured beneath and opening twyer is an air-regulating valve into the which is shown as a plug-valve, the closuree of which is tubular and has a side port through which it opens into thetwyer, as shown in 6 and 8. Connected in the end of said valve and delivering through the plug 6 into'the twyer is an air-blast pipe E, which is connected with a blower of any suitable kind, adapted to produce the desired blast-press sure Within the furnace. Connected in the side of said valve E is an air-relief ipe'E the outlet to which is also control'led by the plug-closure e and which opens to'the atmosphere. The arrangement of said valve is such that when the plug is adjusted toadm t the blast to'the twyer the relief pi-pe E is closed thereb and when the closure is rotated to em ude blast from the twyer or partly exclude the same the blast, or-a 'ortion thereof, is delivered through the re iefipe. This enables the force of the blast to e regulated to suit the requirements of use. The furnace may be construeted in any suitable manner to support the blast-burners in the position described. Conveniently and referafbly, however, the fire-brick which orm the first course above the bottom of the furnace and those in the base are shaped as shown in Fig. 5 to afford an approximately rectangu'lar corner for the furnace at the side or sides through which'the burner or'burners enter, thus facilitating laying up the furnace, insuring the proper angle of the burner with the inner wall, and also simplifying the repairs.

preferred. As shown in Fig. 5, two burners are employed on diametrically opposite sides of the furnace and which are arranged to send the blast in the same direction around the crucible. In this construction the airpipes, the hydrocarbon-pi es, and the-reliefpipes are connected in bot twyers, thusenabling uniformity of action to be secured without difficulty.

The operation is as follows: With 'the furnace constructed as described the metals to be treated are placed within the crucible, if preferred, through the lid. The furnace is then closed, the burners lighted, and the valve E actuated by means of a lever-e to admit the required blast into the fm-naae, said blast being of course proportionate to One or more burners may be employed, as

. lever the amount of hydrocarbon used and the temperature'to be attained, both of which 0 n be" regulated by adjustment of the needlevalve by means of the hand-wheel e and the adjustment of the valve E by means of the Inasmuch as the blast is directed obliquely and downwardly against the inner wall of thefurnace, a centrifugal blast is sent around the crucible, exerting a maximum heating effect, but having no erosive effect thereon. A portion of the ases and fumes escape through the cover; ut the greater part thereof escapes through the stack a, which of. course may be provided with any desired damper for regulating and controllinglthe draft in the same. Owing to the perip eral deflection of the current or currents from the blast the metal within the crucible is quickly and uniformly reduced. The hook c is then released, and the lid is swung up by its counterweight, permitting the removal of the crucible for pourin as usual. During the period following t e reduction of the metal and including the period of pouring and the return of the crucible to the furnace and charging the same the air-blast is deflected from the twyers by rotating the valveplug to direct the blast through the relief pipe or pipes or sufficient thereof to prevent great loss of heat within the furnace while ouring returned to the furnace again charged, either before closing the lid or through the lid D, which is so constructed that should the metal not fill readily-into the crucible a part of the same may extend upwardly within the lid. v

Theblast is thenagain turned on by means of the needle-valve and the lever c and the operation immediately recommences, thus enabling the burners to be continuously used without inconvenience. Should a plurality of furnaces be connected with the same blast-pipe E, the relief-pipes afiord means for cutting out the blast from any one of the furnaces without effecting the blast of the others, and, furthermore, should two'or more burners be used in a single furnace all the burners for a furnace may be connected in the same blast-pipe and with the same reliefipes, thus insuring uniformity for both urners. Should a crucible break, the passa e in the bottom of the furnace, which is or 'narily stopped with clay, is picked open,

rmitting the molten metal to run from the fiimace without injury either to the furnace or metal.

Owing to simple construction of the furnace and the fact that the individual blocks or bricks of fire-clay or other refractory material are molded to lay readily to the'construction, afiording ample support for the burners, it is evident that the construction is exceedingly cheap, affords extreme simplicity, great durability, and economy of operation and maintenance. Furthermore, it is The crucible can be immediately;

evident that many details of arrangement and construction may be varied. I therefore do not purpose limiting this application for patent otherwise than necessitated in the prior art.

I. claim as .my invention- 1. A furnace of the class described having a fire-pot .provided with a rounded bottom having a greater interior diameter than the top and a peripherally and downwardly directed lblast burner, opening obli uely through the side of the furnace and a apted to direct a reducing-blast|centrifugally around the furnace-crucible.

2. In a furnace of the class described, a crucible therein, blast-burners directed downwardly and inwardly of the furnace approximately tangent to its inner periphery and a concave bottom in said furnace adapted to direct the blast from the burners in an upwardly-directed spiral about the crucible.

3. In a furnace of the class described a crucible, a support therefor afiording with the furnace-bottom a rounded deflecting-surface, one or more burners arranged to direct its blast obliquely against the inner periphery of the furnace and downwardly against said deflecting-surface and means for regulating the blast of said burners.

4. In a melting-furnace the combination with a furnace constructed of molded refractory material, of an outer-metallic casing fitted thereto, a stack leading from the furnace, one or more blast-burners opening obliquely and downwardly through the side wall of the furnace and directing the blast therefrom away from but centrifugally around the crucible, means for deflecting said blast from the bottom of the furnace spirally upward and a regulating-valve for the blast acting to direct the same into or out of the furnace.

5. In a metal-melting furnace the combination with a crucible-support of upwardlyconverging, encircling side walls surrounding the crucible and aifordin with the support a rounded bottom adapte to direct the blast in an upwardly-directed spiral and one or more hydrocarbdn blast-burners o ening ob liquely inwardly and downwardly toward said bottom, said side walls affording an increased thickness at the point of insertion of the burner.

6. In a melting furnace, a fire-pot having an enlarged bottom, a crucible's'up'port therein affording with the bottom a rounded deflecting-surface, a crucible thereon and one or more blast-burners extending through the walls of the furnace and adapted to direct a blast against said deflecting-surface and in gp upwardly-directed spiral aboutthe cruci- 7. In a meltin -furnace the combination with the side wa ls thereof of one or more blast-burners openin therethrough nearthe bottom and directe both tangentially and downwardly, a crucible and a su port thereon the furnace, a cam-lever carried on the lid for aflordin with the walls of -t e furnace 'a adapted to be engaged thereby and hold the rounded de eating-surface adapted to direct lid in closed position and counterweights for the blast centnifugally and upwardly about said lid. 5 the crucible. In testimony whereof I have hereunto sub- 8. In a meltin -fur'nace the combination scribed my name in the presence of two-sub- }wlithg fireigogfig a orueiible thergin, ail lid scribing witnesses.

'nge on t e nace an rovi e Wit an inverted conical aperture tfierethrough, reg- I ALFRED FISHER 1o istering with the top of said crucible, a cover Witnesses:

adagted to close said aperture and provided C. W. HILLS, wit aoentral vent therein, a hook pivoted W. W WITHENn'ImY. 

